Research shows accidents at two-lane roundabouts decrease over time

On Behalf of | Mar 18, 2022 | Motor Vehicle Accidents

With roundabouts finally being built in the Lehigh Valley, it is time for drivers to learn how to use them.

Roundabouts can feel dangerous for drivers who are not used to using them. However, a 2019 review of research by the Insurance Institute for Highway Safety suggests that roundabouts with two lanes of traffic become safer as local drivers get used to the flow of vehicles.

The dangers of dual-lane roundabouts

The IIHS notes that while single-lane roundabouts successfully eliminate most types of collisions that commonly occur at intersections, double-lane circles introduce the potential for more crashes. Failure to yield right-of-way is the most common cause of traffic circle accidents. According to the agency, adding a second lane statistically increases the collision rate rather than mitigating traffic as intended, but this effect is often temporary.

Findings of the study

Reviewing collision trends for more than 300 traffic circles in Washington state, the IIHS researchers focused on annual crash rates for roundabouts constructed from 2009 to 2015. Two-lane roundabouts saw an average crash decrease of 9% annually and almost a 33% decrease in accidents causing serious injuries each year. Crashes involving failure to yield went down by about 11 percent each year.

In comparison, debilitating auto accident injuries at single-lane roundabouts fell by 19% each year after construction, with an overall crash decrease of 7% per year. Speed-related crashes, a common issue in single-lane circles, decreased by 19% per year.

The IIHS recommends improving markings and signs to help drivers become familiar with new roundabouts in their communities, including noticeable yield and speed limit signs.

Review the study if you have concerns about driving in a roundabout.